Ecology & Biomes – Natural Selection Review

Question-and-answer flashcards covering fitness, natural selection requirements, characteristics of major terrestrial and aquatic biomes, and the rock pocket mouse case study.

In evolutionary biology, how is an individual’s fitness measured?

By the number of surviving offspring it produces compared to others in the population.

Name the three necessary conditions for evolution by natural selection.

1) Variation in traits, 2) Heritability of those traits, and 3) Differential reproductive success (fitness differences).

What climate and vegetation characterize the tundra biome?

Very cold temperatures, low precipitation, permafrost soils, and plant life dominated by mosses and lichens.

Describe the key environmental conditions and common vegetation of the desert biome.

Extremely low precipitation with hot or cold temperatures; vegetation includes water-storing plants such as cacti and succulents.

Why is the tropical rainforest biome noted for high biodiversity?

It has a warm climate with consistently high rainfall, creating ideal conditions for a vast variety of plant and animal species.

Which biome is dominated by grasses, experiences moderate rainfall, and is often shaped by frequent fires?

Grasslands.

What are the defining features of a deciduous forest?

Four distinct seasons and trees that shed their leaves annually.

Which biome, also called the taiga, is known for cold, snowy winters and evergreen coniferous trees?

The coniferous forest (taiga).

What climatic pattern distinguishes the chaparral biome?

Hot, dry summers followed by mild, wet winters.

How do freshwater and marine biomes differ in salinity?

Freshwater biomes (rivers, lakes, streams) have low salinity, while marine biomes (oceans, coral reefs) have high salinity.

Why did darker fur become more common in rock pocket mice living on volcanic rock?

Natural selection favored mice with darker fur because their camouflage reduced predation, increasing their survival and reproductive success.

What evolutionary concept is illustrated by the rock pocket mouse’s fur-color change on lava flows?

Adaptation through natural selection in response to environmental change (camouflage to avoid predators).